[Zubersoft]

It doesn't sound like you are using the half page display mode in portrait, because what you've described is exactly what it does - you can turn a half page at a time, and it just flips the top or bottom half of the page. You can also adjust the half page turn position with the blue bar. This video demonstrates how to change display modes: https://www.youtube.com/watch?v=V_8GXnlNfm0

If you want to change how pages are scaled, change the default display mode: https://www.youtube.com/watch?v=WXVGHa96ssw

Mike